Communication Systems

Modulation And Demodulation

Today’s communication system is a complex system of numerous components working in a comprehensive fashion together round the clock. However, one of the primary key components of the Communication system is the MODEM. Shortened for the term Modulator and Demodulator, this is a paired system that has revolutionized the global communication scenario. Thus, we will study modulation and demodulation in detail here.

modulation and demodulation

Introduction to Modulation and Demodulation

Much of the time, we need to regulate the signal to higher recurrence bands, we generally refer to it as the radio frequency (RF) bands, to suit the spread attributes of the correspondence channels.

Further, the least difficult RF channel is the non-dispersive channel which changes the amplitude and period of the communicated signal. Moreover, there are two different ways to perform demodulation over the non-dispersive channel.

The first path is to assess the phase bending and utilize the coordinated Filter as in a baseband correspondence framework. In addition, this strategy generally alludes to as sound demodulation. The subsequent methodology, which we call non-coherent demodulation, is to try not to utilize the phase data in the demodulation process at all. Thus, we will discuss this in detail over here.

Basic Working concept of Modem

modulation and demodulation

Understanding  Modulation

Modulation is the process of converting data into electrical signals or optical carrier signals which optimize for transmission. Thus, slightly similar to a sine wave, a carrier wave composes of constant frequency,

Types of modulation

There are many three types of modulation:

Frequency Modulation – When the frequency of a carrier wave changes or varies due to the change of the frequency of the signal modulation while the amplitude and frequency are at a constant state, we term it as Frequency modulation.

Phase Modulation – When the phase of a high-frequency carrier wave changes or varies due to the change of the phase of the signal modulation while the amplitude and frequency are at a constant state, we term it as Phase modulation.

Amplitude Modulation – When the amplitude of a high-frequency carrier wave changes or varies due to the change of the amplitude of the signal modulation while the phase and frequency are at a constant state, we term it as Amplitude modulation.

Mechanism of Modulations

Though modulation can occur in a number of ways. Thus, there are a few primary modulation mechanisms that we mainly take into practical and usable categorization. The primary 4 categories of the mechanism of Modulations are:

  1. Analogue modulation
  2. Digital modulation
  3. Pulse modulation
  4. Spread spectrum method

The need for Modulation in a system is very important for numerous reasons. The baseband signal cannot transfer directly. Thus, to transfer such signal to a longer distance, by modulating with a high-frequency signal wave, the signal strength has to increase which doesn’t affect any parameter of the signal.

Understanding Demodulation

Demodulation is getting the original form of data modulated carrier wave. To recover the data from a modulator carrier wave – a demodulator signal circuit comes in use. There are different types of demodulators too. The demodulator output signal may describe as a sound, binary data, or pictures.

modulation and demodulation

Need for Demodulation

A radio frequency carrier wave carrying within a wireless signal- modulated by audio frequency. With high frequency, The diaphragm of a telephone receiver cannot vibrate. Moreover, this frequency is beyond the audible range of the human ear. To separate the audio frequencies from radio- frequency carrier waves – a demodulator comes in use.

Differentiating between Modulation and Demodulation

While modulation helps in the collection of data into the carrier, demodulation helps in the recovery of data. However, there are a few distinguishable difference between both of them as a whole.

– In a communication system modulation is done at the transmitter side. Whereas Demodulation is done at the receiver side of a communication system.

– In modulation, the original message signal is mixed with a carrier wave whose parameters are required to be changed. In demodulation, the combination of carrier and message signal are separated from each other, to have an original information signal.

– Modulation essentially occurs to transmit data to a longer distance. Demodulation takes place to retain the original form of the signal

FAQ on Modulation And Demodulation

Question 1: What is modulation in a computer network?

Answer 1: Modulation helps in adding information into a carrier. This information transmits in periodic waveforms that decodes into a readable format using a Computer network.

Question 2: Which is the best modulation technique?

Answer 2: Amplitude modulations are more prone to noise distortion, however, Phase and Frequency Modulation works much better at a constant noise level and requires lesser power for clearer transmissions.

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